Visweshwar Ram Marthi

Fellow - D
Email: viswesh [at]
Phone: 02025719229
Extn: 9229
Office: F204B
National Centre for Radio Astrophysics
Tata Institute of Fundamental Research
Savitribai Phule Pune University Campus,
Pune 411 007
Maharashtra, INDIA

Main Research Areas: Statistical methods for 21-cm cosmology; Astronomy signal processing; The Warm Ionized Medium; Interstellar scintillation; Very Long Baseline Interferometry.



Visweshwar Ram Marthi earned his bachelor's and master's degrees in Electrical Engineering from the University of Madras and National Institute of Technology, Tiruchirappalli, respectively. Marthi had a brief stint in the telecommunication industry after a Masters in Electrical Engineering. For his Ph.D., he worked on the upgrade for the Ooty Radio Telescope, developing calibration and statistical methods for the redshifted 21-cm experiment. After his Ph.D., he worked as a postdoctoral fellow at the Canadian Institute of Theoretical Astrophysics at the University of Toronto, Canada. He returned to NCRA in September 2019.

Research description:

Viswesh's research interests lie mainly in the area of astronomy techniques which employ signal processing and semi-analytical or numerical methods that are amenable to algorithmic representation. For the Ooty Wide Field Array, he produced a complete description of the instrument and the radio sky at 327 MHz, studying the effects of the instrument on the observed foregrounds. His current interests have expanded to include the physical properties of, and the conditions in, the ionized interstellar medium, studying it through interstellar scintillation and employing VLBI techniques.

Selected publications:

1.  An analytical method to simulate the H I 21-cm visibility signal for intensity mapping experiments (A.  K. Sarkar, S. Bharadwaj & V. R. Marthi, 2018, MNRAS, 473, 261).

2. Simulated predictions for H I at z = 3.35 with the Ooty Wide Field Array - I. Instrument and the foregrounds (V. R. Marthi et al. , 2017, MNRAS, 471, 3112).

3. Simulating the z = 3.35 HI 21-cm Visibility Signal for the
Ooty Wide Field Array (OWFA) (S. Chatterjee, S. Bharadwaj & V. R. Marthi, 2017, JApA, 38, 15).

4. Prowess - A Software Model for the Ooty Wide Field Array (V. R. Marthi, 2017, JApA, 38, 12).

5. Non-linear Redundancy Calibration (V. Marthi & J. N. Chengalur 2014, MNRAS, 437, 524)

6. The Central Point Source in G76.9+1.0 (V. Marthi et al. 2011, MNRAS, 416, 2560)

7. A Search for the 55-MHz OH line (V. Marthi & J. N. Chengalur 2010, MNRAS, 407, 258)